Monitored medico-surgical approach to the treatment of cystic hydatidosis.

Introduction For over 50 years the consensus of opinion has been that surgical intervention is the only effective way of treating human cystic hydatidosis caused by Echinococcus granulous (1). Numerous reports have appeared about the advantages of various operative techniques and approaches to patient management [2,3]. However, despite evident advances in technology, a significant proportion (10-15%) of individuals fail to recover, owing to the inaccessibility of their lesions or chronic host tissue reactions [4,5]. The introduction of effective chemotherapy with benzimidazole derivatives has recently provided fresh hopes for persistent cases of hydatidosis [6-9]. However, this has creatd coern about the proper selection of patients for chemotherapy, and the subsequent provision of adequate, standard criteria to assess progress or recovery at the early stages of, during the course of, and after therapy [9-12]. Since the antigenic activity induced by E. granulosus can be detected by analysing the host immune response, we have developed a monitoring system to determine variations in the specific IgG and IgM and circulating immunocomplexes in patients. The results obtained can be used to gauge the progress of patients still under treatment (13 and R.M. Matossian et al., unpublished results, 1991). In this article we present the selected case histories of six patients with complicated abdominal hydatidosis for whom immunological monitoring was valuable in choosing an adequate form of therapy, and which led to improved clinical status or cure. Materials and methods Patients selection and management Six patienst ( 1 male and 5 females, aged 15-45 years) with multifocal abdominal hydatidosis were selected at random for the study from a group undergoing combined albendazole therapy and surgery. At the start of the study each patients underwent a complete physical examination. Also blood samples were taken at intervals for differential counts, biochemical investigations (SGOT, SGPT), and serology. Urine analysis was routine. An ultrasound radiograph or ultrasound computed tomograph was made initially and whenever needed thereafter. The patients received albendazole tablets (10-14 mg/kg body weight per day) in cycles of 6 weeks separated by drug-free intervals of 4 weeks or longer. Serum samples were obtained generally at monthly visits and were stored at -20 [degrees]C. Whole hydatid cyst fluid (HCF) antigen, which had previously been tested for high potency, was obtained from single cysts of ovine or human origin. Samples (5 ml) were stored at -20 [degrees]C. Indirect haemagglutination (IHA) tests were carried out following the method described by Matossian et al. [13] Latex agglutination tests for rheumatoid factor in serum were performed using a commercially available reagent (Rapid-Tex RF, Behring). Enzyme immunoassays Specific antibodies. Anti-echinococcus antibodies were assayed in human sera usinga peroxidase micro-ELISA (enzyme-linked immunosorbent assay) described by Craig [15] and modified by Matossian et al. [13]. Specific immunocomplexes. These were assayed in whole human sera using a capture antibody method described by Craig [5]. The procedure was similar to that followed for the detection of specific antibodies, except that the wells of the microassay plates were sensitized with sheep serum containing anti-HCF antibodies (kindly provided by Dr P. Craig). The cut-off point for the discrimination of positive and negative sera was taken to be twice the absorbance of the mean of a negative serum pool (3 donors) tested in triplicate. All sera from individual patients were tested simultaneously and in triplicate [13]. Results Table 1 shows the salient clinical data and progress of the six patients throughout their medico-surgical management, while details of their sequential immune responses are contained in Table 2. …